1. Field of the Invention
This invention relates to food compositions for human consumption comprising creatine and to a method of providing such compositions.
2. Background of the Technology
In the last few years there has been considerable interest among athletes in creatine, which occurs abundantly in skeletal muscle. Creatine plays a pivotal role in the regulation and homeostasis of skeletal muscle energy metabolism and it is now generally accepted that the maintenance of phospho-creatine availability is important to the continuation of muscle force production. Creatine may also be involved in other processes concerned with protein synthesis and hypertrophy of muscle fibres during training. Although creatine synthesis occurs in the liver, kidney and pancreas it has been known for some time that the oral ingestion of creatine will add to the whole body creatine pool, and it has been shown that the ingestion of 20 to 30 g creatine monohydrate (Cr.H2O) per day for several days can lead to a greater than 20% increase in human skeletal muscle total creatine content. Thus, WO94/02127 discloses the administration of creatine monohydrate in amounts of at least 15 g (or 0.2-0.4 g/kg body weight) per day, for at least 2 days, for increasing muscular strength.
In fact, it was subsequently found that after several days of supplementation (20 g per day) with creatine monohydrate in order to attain initial elevation of the tissue stores, thereafter it takes no more than 2 to 3 g per day to maintain the newly elevated concentration. Supplementation with any bioavailable source of creatine (i.e. creatine supplementation) in an appropriate dose can provide improvements to athletes involved in explosive events, which include all events lasting from a few seconds to a few minutes (such as sprinting, swimming, weight-lifting etc). Endurance performance in events lasting longer than about 30 minutes appear less affected by creatine supplementation except where this involves short periods of increased energy output particularly when the local muscle carbohydrate stores have become depleted. Creatine is a normal food component and is not a drug and its use is not contrary to official regulations. It is possible that the greatest benefits of creatine supplementation are experienced by the elderly, vegetarians or those who eat no meat or fish, since these people tend to have low muscle creatine contents. Also, recent studies have shown that creatine can reduce mental fatigue (Watanabe et al., Neuroscience Research, 42 (2002) 279-285).
Furthermore, creatine and its derivatives have been used in the past for the preparation of products with a meaty or savory flavor. For instance, Tonsbeek (U.S. Pat. No. 3,615,600) discloses and is concerned with artificial flavoring, describing mixtures imparting a meaty flavor to foods. Similarly de Rooji (U.S. Pat. No. 4,464,409) is concerned with meat flavoring. Yamazaki (JP-A-59035663) prepares a meat flavor by heating a mixture comprising creatine at pH 5.0-7.0 at a temperature of 80-130° C. for 30-120 minutes. Under these conditions most of the creatine is converted to creatinine.
The inventors believe that it would not occur to the persons skilled in the art to add creatinine (used hitherto as a meat or savory flavoring agent) to compositions which were intended to have a flavor (especially a fruit flavor) other than meaty or savory. The person skilled in the art might have expected the addition of creatinine to result in an unpalatable combination of fruit and meat flavors, whereas in fact the inventors have found that the resulting combination does not impart an undesirable meaty flavor.
WO 97/45026 discloses an acidic composition for human consumption comprising creatine and its derivatives, the composition being provided as a dry powder or in liquid or semi-liquid form. The compositions disclosed therein are stable at refrigerated temperatures (4° C.) for prolonged periods but stable at ambient temperature for relatively short periods (e.g., up to, but not exceeding, 7 days).
WO 00/74500 discloses compositions comprising creatine and its derivatives suspended in aloe vera gel, which compositions were stable (with respect to the conversion of creatine to creatinine) at room temperature for 2 weeks or more, depending on the initial concentration of creatine in the composition.
Both WO 97/45026 and WO 00/74500 stress the desirability of preventing the conversion of creatine to creatinine.